This invention relates to a pager receiver operable in response to a specific call number signal preassigned to the pager receiver.
A pager receiver is classified into two types one of which has no display and the other of which provides displays. The former receiver generates only an audible tone on reception of the specific call number signal and will be called a receiver of a tone-only type or a tone-only type receiver. On the other hand, the latter receiver can display a message in addition to generation of an audible tone and will hereinafter be called a receiver of a display type or a display type receiver. Although this description will mainly be directed in the preamble of the instant specification to the receiver of the tone-only type, this invention is equally well applicable to the receiver of the display type.
In the tone-only type receiver, it is impossible to visually display a directory number of a calling subscriber when a called subscriber or a possessor is called by generation of the audible tone. Under the circumstances, a prescribed telephone number is previously determined between the calling subscriber and the possessor. The possessor is communicable with the calling subscriber by dialing the prescribed telephone number.
In order to dispense with dialing the prescribed telephone number, an automatic dialing device is known which may be named an autodialer and which comprises a memory for memorizing a preselected telephone number and a converter for converting the preselected telephone number into a corresponding dial tone. With this structure, the dial tone can automatically be sent from the automatic dialing device through a telephone set and a telephone line to a calling subscriber when the automatic dialing device is energized by manipulation of the possessor.
Even when the automatic dialing device is included in the tone-only type receiver, the calling subscriber must stay near a telephone identified by the prescribed telephone number until the calling subscriber is called back from the possessor. Therefore, the tone-only type receiver is inconvenient in that a restriction is imposed on a geographic position or location of the calling subscriber.
Intervention of a third party or person might be considered between the possessor and the calling subscriber so as to remove the above-mentioned restriction of the geographic location of the calling subscriber. In this event, the possessor can be connected to the calling subscriber through the third person. If the calling subscriber informs the third party of his or her location, the calling subscriber can always speak with the possessor.
However, such intervention of the third party requires extra labor and is troublesome.
Further consideration is made about assigning to a single tone-only type receiver a plurality of different call numbers which may be given to individual calling subscribers. In this case, reception of the different call number signals is distinguished from one another by individual pitch tones, respectively. Therefore, the possessor can recognize the individual calling subscribers by audibly discriminating the respective calling subscribers. In fact, it is technically confirmed that the number of the call numbers assigned to the single pager receiver is increased to sixteen at maximum. This means that such a tone-only type receiver can access sixteen calling subscribers at maximum because the call numbers have to be made to correspond to the respective calling subscribers.
At any rate, an assignment of the plurality of call numbers to the single tone-only type receiver restricts the number of calling subscribers communicable with the pager receiver and becomes an unfavorable bar against effective use of the call numbers because the plurality of call numbers are exclusively used by the single tone-only type receiver.
Moreover, a subscriber for the above-mentioned tone-only type receiver should pay fees for the plurality of call numbers and must owe an extra economical duty.